feat(icons): add oauth2-proxy (#1022)

Co-authored-by: Dashboard Icons Manager <193821040+dashboard-icons-manager[bot]@users.noreply.github.com>

tree.json

@@ -1255,6 +1255,7 @@
         "nzbhydra.png",
         "nzbhydra2-light.png",
         "nzbhydra2.png",
+        "oauth2-proxy.png",
         "obico.png",
         "obitalk.png",
         "observium.png",
@@ -3174,6 +3175,7 @@
         "nzbget.svg",
         "nzbhydra2-light.svg",
         "nzbhydra2.svg",
+        "oauth2-proxy.svg",
         "obico.svg",
         "obsidian.svg",
         "obtainium.svg",
@@ -5122,6 +5124,7 @@
         "nzbhydra.webp",
         "nzbhydra2-light.webp",
         "nzbhydra2.webp",
+        "oauth2-proxy.webp",
         "obico.webp",
         "obitalk.webp",
         "observium.webp",